Is there any differences between a MAF TPI base and a SD TPI base? Need to know for my engine swap.

Kevin

 

They are the same. Allen

 

This is an incorrect statement. There were 3 different styles of OEM TPI's produced. It is important to match up correctly the Baseplate, Runners, Plenum & Throttle Body or you can end up with a major headache.

Here is a good article on Identifying GM's Tuned-Port Injection Units:

http://www.classictrucksweb.com/tech/0402cl_tpi/

Bill

 

The question was speed density versus MAF. I agree that there are different vintages of TPI components. It's my opinion you can use any one of them for SD or MAF. The changes are in the computer and the wiring harness etc. It also possible I miss understood the question. Allen

 

I know about all the # different types of TPI. My question was will a SD Intake base work with the runners and pletnum from MAF.

Kevin

 

Runners plenum and fuel rail? The 89 should work.

 

O'Kay

First off, The Base Intake break down into 3 styles:

1. '85-86 IROCs, T/As, and Corvettes with cast-iron heads with outside valve-cover bolt holes (early-style).

2. '87-91 Corvette intake used a heat-riser tube off of the passenger-side header and has a water crossover at the back to relieve hot spots on the back of the aluminum heads.

3. '87-92 IROCs and T/As with cast-iron heads with center-bolt valve covers.

FYI - The cold start sensor was removed from the 89 - 92 Intakes

Secondly, The Runners:

1. All the passenger-side TPI tubes for all '85-92 models are the same.

2. '85-88 units driver-side TPI tubes had the ninth injector port.

3. '89-92 F-body and '89-91 Corvette driver-side TPI tubes didn't.

In Third Place, The Plenum:

1. '85-88 has a cold start passage and an IAC passage.

2. '89, eliminated both the cold start passage and the IAC passage from the front of the plenum.

3. '90-92 added a MAP boss

YFI - Early model Throttle Bodies can not be used on a late model Plenum, But Late model throttle bodies can be used on earlie model plenums.

If your converting your 89 to a SD, the only mod that I can think of other than you Harness, Ecm and Sensors would be adding a fitting for your MAP

Bill

 

Allen, I just re-read his question again for the 50th time. We may have all missed it. Or maybe it was just me. I just noticed that he's going to use a '92 350 TPI and plant it into his '89. If this is the case, worring about the differences between the intake manifolds doesn't matter. All he has to worry about is Engine Wiring Harness, Ecm and Sensors.

Anybody agree or disagree???

Bill